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arXiv · 2408.01299

Complete Self-Testing of a System of Remote Superconducting Qubits

Simon Storz·Anatoly Kulikov·Josua D. Schär·Victor Barizien·Xavier Valcarce·Florence Berterottière·Nicolas Sangouard·Jean-Daniel Bancal·Andreas Wallraff
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Abstract

Self-testing protocols enable the certification of quantum systems in a device-independent manner, i.e. without knowledge of the inner workings of the quantum devices under test. Here, we demonstrate this high standard for characterization routines with superconducting circuits, a prime platform for building large-scale quantum computing systems. We first develop the missing theory allowing for the self-testing of Pauli measurements. We then self-test Bell pair generation and measurements at the same time, performing a complete self-test in a system composed of two entangled superconducting circuits operated at a separation of 30 meters. In an experiment based on 17 million trials, we measure an average CHSH (Clauser-Horne-Shimony-Holt) S-value of 2.236. Without relying on additional assumptions on the experimental setup, we certify an average Bell state fidelity of at least 58.9% and an average measurement fidelity of at least 89.5% in a device-independent manner, both with 99% confidence. This enables applications in the field of distributed quantum computing and communication with superconducting circuits, such as delegated quantum computing.

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Simon Storz, Anatoly Kulikov, Josua D. Schär, Victor Barizien, Xavier Valcarce, Florence Berterottière, Nicolas Sangouard, Jean-Daniel Bancal, Andreas Wallraff. 2024-08-02. Complete Self-Testing of a System of Remote Superconducting Qubits. https://doi.org/10.1103/nv7d-k3wr

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